<?php
/**
 * Zend Framework
 *
 * LICENSE
 *
 * This source file is subject to the new BSD license that is bundled
 * with this package in the file LICENSE.txt.
 * It is also available through the world-wide-web at this URL:
 * http://framework.zend.com/license/new-bsd
 * If you did not receive a copy of the license and are unable to
 * obtain it through the world-wide-web, please send an email
 * to license@zend.com so we can send you a copy immediately.
 *
 * @category   Zend
 * @package    Zend_Pdf
 * @copyright  Copyright (c) 2005-2009 Zend Technologies USA Inc. (http://www.zend.com)
 * @license    http://framework.zend.com/license/new-bsd     New BSD License
 * @version    $Id: Binary.php 18985 2009-11-14 18:51:34Z alexander $
 */


/** Zend_Pdf_Element_String */
require_once 'Zend/Pdf/Element/String.php';


/**
 * PDF file 'binary string' element implementation
 *
 * @category   Zend
 * @package    Zend_Pdf
 * @copyright  Copyright (c) 2005-2009 Zend Technologies USA Inc. (http://www.zend.com)
 * @license    http://framework.zend.com/license/new-bsd     New BSD License
 */
class Zend_Pdf_Element_String_Binary extends Zend_Pdf_Element_String
{
	/**
	 * Object value
	 *
	 * @var string
	 */
	public $value;


	/**
	 * Escape string according to the PDF rules
	 *
	 * @param string $inStr
	 * @return string
	 */
	public static function escape($inStr)
	{
		return strtoupper(bin2hex($inStr));
	}


	/**
	 * Unescape string according to the PDF rules
	 *
	 * @param string $inStr
	 * @return string
	 */
	public static function unescape($inStr)
	{
		$chunks = array();
		$offset = 0;
		$length = 0;
		while ($offset < strlen($inStr)) {
			// Collect hexadecimal characters
			$start = $offset;
			$offset += strspn($inStr, "0123456789abcdefABCDEF", $offset);
			$chunks[] = substr($inStr, $start, $offset - $start);
			$length += strlen(end($chunks));

			// Skip non-hexadecimal characters
			$offset += strcspn($inStr, "0123456789abcdefABCDEF", $offset);
		}
		if ($length % 2 != 0) {
			// We have odd number of digits.
			// Final digit is assumed to be '0'
			$chunks[] = '0';
		}

		return pack('H*' , implode($chunks));
	}


	/**
	 * Return object as string
	 *
	 * @param Zend_Pdf_Factory $factory
	 * @return string
	 */
	public function toString($factory = null)
	{
		return '<' . self::escape((string)$this->value) . '>';
	}
}
